Security of their business premises is important to companies, especially for those companies which have personal computers. The personal computers are becoming smaller and more easily portable (particularly laptop computers and network computers) at the same time that personal computers are providing an increasing amount of data processing to the desktop of the individual worker. Each personal computer is expensive in initial hardware costs, with software and service costs adding to the value of the personal computers, and personal computers store an increasing amount of data for a typical business organization. Loss of any of the personal computers would represent a loss of an investment as well as a decrease in the productivity of the business operation, in some cases reducing substantially the productivity of a worker.
While some businesses are operated around the clock every day, many are operated only part of the time, with the rest of the time, the facilities are expected to be idle. This idle time provides a risk, since the absence of authorized personnel implies an opportunity for devious (criminal) activity because no one is watching. This devious or criminal activity could range from stealing either equipment or data or altering the data to make it unusable or unreliable. Such devious or criminal activity can result from a person, either an employee or a visitor or even a stranger, getting into an area where the people are otherwise not present, as after normal working hours. It would desirable to detect the presence of an intruder after normal business hours so that the security can investigate and take appropriate steps to remove an inappropriate visitor.
Of course, one way to monitor premises for visitors in places where they aren't supposed to be at times when they are not supposed to be there is to install a security system of either cameras or motion detectors in the region, then monitor those devices for improper activity. But, a security system normally involves running new cables to attach the sensor devices such as motion detectors or cameras to a central monitoring station. Such cabling is expensive to run and may be the subject of additional requirements such as building codes and require a building permit to install.
It would be desirable to use the personal computers which are in place to assist in providing monitoring, but the personal computers are typically in their operational mode only during the normal working hours and are turned to non-operational mode when the working day ends, making it difficult to use the personal computers in monitoring of after-hours activities on the business premises. Further, leaving the personal computers in their operational mode would have disadvantages, both in terms of power consumption and in terms of device life, particularly the life of the monitor attached to the personal computer, where the coatings on the screen tend to degrade as the monitor accumulated hours of operation, a reason that "screen savers" have come into use to reduce the amount of deterioration of the coatings on the monitor.
Security devices may be operated individually or using remote communications techniques, but these are usually suitable only for small systems or line-of-sight applications. Each sensor in a security system could include its own visual or audible alarm, a system which would work well if the monitoring station could see or hear all the locations. The security system could communicate over infrared communications if the sensor and the receiver were in a line of sight relationship. A security system could communicate using radio or cell phone communications if the system had enough capabilities without becoming too expensive.
Other limitations and disadvantages of the prior art systems for providing security of premises will be apparent to those skilled in the relevant arts.